I ran a quick search of the archive and found this thread: http://ferrarichat.com/forum/showthread.php?p=138468205 It lists the OBDII codes for a 360. I had a look in it (on page 18) and there is no P1447 code. It did list a P144g, that came right after the P1446, and the P144g is for a "catalyst bypass flap circuit". So maybe (??????????????) you could have a bad bypass valve on your y-pipe going into the top of the muffler???? I'm just totally guessing here because those codes are for a 360. You may indeed have something completely different. What you really need are the actual codes for the 355 Motronic 5.2.
Agreed. Could be catalyst or bypass related. I had some issues in this area that turned out to be wiring/connector issues. First check the bypass valve by removing the vacuum hose and applying a vacuum to see if the flap moves. Then check the electrical connections to the vacuum solenoids. These are behind the passenger (USA) wheel towards the back of the car. My issue was the electrical contact at this point. When I unplugged the connectors, they were badly corroded. I cleaned them and it seemed to resolve this issue. You might also want to verify that you don't have any leaks in your vacuum lines. If that all checks out, it could be catalyst related. You could check the two ECUs which are mounted in the same area as the solenoids. They tend to crack and cause issues. There is also an ECU on the driver side in the same area. These ECUs are interchangeable, so you can swap the cables between two ECUs and see if your code changes, which would indicate the same problem, but at a different ECU. Just some thoughts.
I just read your other thread in the tech section, and I that code P1447 is for your "slow down" light not working. Looks like the codes for a 360 don't work for a 355, or maybe just for this particular code. After all it wasn't listed and I did refer to a different code. Oh well I tried. I wonder if someone has the actual OBDII codes for the 355 Motronic 5.2? That way the next guy asking a question about his 355 check engine light will be able to find the code himself.
Can't speak of the M2.7 but I confirm the info is correct for M5.2: P1447: check in the Instrument Cluster if the bulb is burned out or if the bulb is good if it's sitting right in the bulb socket for SLOW DOWN light. Once confirmed the SLOW DOWN light comes up along others before starting up the engine (turn the ignition key to "ON" position), reset the CHECK ENGINE and you're good to go. Note: the M5.2 ECU checks if the SLOW DOWN bulb is OK every 60 minutes since CHECK ENGINE reset while the engine is working. This is how the car notifies you the SLOW DOWN light is not working by firing up the CHECK ENGINE light w/ this code so you wouldn't burn out your cats if exhausts get overheated. Very mindful and smart.
It could be the SDECU or TC after the BP valve. That TC tells the Motronics if the bypass valve is opening or not. I'm not sure of the voltage requirements to trigger codes. You could start by swapping the components that are right next to each other on the subpanel on the right side of the car. You don't need to physically remove them from there, just switch the connectors around. Label them and see if the code moves to the right bank (Bank1).
Wow, resurrecting an old thread here but it's timely for me. My '97 355 is throwing a P1448 code. Not sure if the codes for the 355 are the same as those for the 360, but I believe that it does relate to the BP valve (something as simple as wiring issue or vacuum leak to as expensive as needing a new BP valve). Interested to know if anyone else has seen this code and how they diagnosed/fixed the issue. Fwiw, I'm getting the CEL light but not a slow down light. Does anyone have a set of the unique Ferrari codes for the 355 M5.2? There's one available in PDF format for the 360, http://www.unixboxes.com/F360_ECU_codes.pdf, but I haven't something similar for the 355.
To settle a score from, 2009... (wow who dragged up this old thread?): P1445 = Passenger side CAT ECU / thermocouple / O2 sensor fault P1446 = CEL burnt out or not installed P1447 = Slow Down light burn out or not installed P1448 = Bypass valve fault / thermocouple fault P1449 = Drivers side CAT ECU / thermocouple / O2 sensor fault
The OP has an F12 now to go with his 308 and TR. F355 codes are probably not on his high priority list.
